1. Field
The presently disclosed embodiment relates to methods of measuring a social relationship, and more particularly, to an intimacy measuring method based on heart rhythm coherence (HRC) and a system using the intimacy measuring method.
2. Brief Description of Related Developments
Social cognition or social interaction denotes understanding of a mental state or behavior of a target of communication. A sympathetic reaction with other people is required to understand mental states or behaviors of the other people (Krueger, et al. “Gestural Coupling and Social Cognition: Mobius Syndrome as a Case Study”. Frontiers in Human Neuroscience, Vol. 6, 2012). Many researches into social cognition or social interaction have been recently being conducted. In these researches, synchronization or entrainment is considered as an important concept. Synchronization is a phenomenon in which, when people socially interact with one another, biorhythms of the people are harmonized (Yun, et al. “Interpersonal Body and Neural Synchronization as a Marker of Implicit Social Interaction”. Scientific Reports, Issue 2:959, December, 2012). This synchronization phenomenon may not only occur between people but also in objects or natural phenomena. For example, when pendulums of several clocks swing horizontally at different speeds, the pendulums may swing horizontally in the same direction and at the same speed due to synchronization (Bennett, et al. “Huygens's Clocks”. The Royal Society, Issue 458, pp. 563-579 2002), and firefly lights that are twinkling individually are synchronized at one moment and then simultaneously twinkle together at the same speed (Buck, et al. “Synchronous Fireflies”. Scientific American, Issue 234, pp. 74-85, 1976).
This synchronization phenomenon occurs among people. A representative example of the synchronization is a phenomenon in which two people walk in step with each other at the same interval (Schmidt, et al. “Coordination: Neural, Behavioral, and Social Dynamics”. Springer, 2008; Burgoon, et al. “Interpersonal Adaptation: Dyadic Interaction Patterns”. Cambridge University Press, 1995). In a study of Yun, et al., (2012), synchronizations between finger movements occurred unconsciously between two subjects were compared. This study reported that synchronization between finger movements of two subjects occurred and neural activation of the brain greatly increased when the two subjects perform a cooperative operation, compared with when the two subjects do not perform a cooperative operation. In another study, synchronizations between finger movements of subjects were compared, and it was reported that greater synchronization occurred when the fingers of the subjects move at the same speed than when the fingers of the subjects move at different speeds (Lakens, Daniël. “Movement Synchrony and Perceived Entitativity”. Journal of Experimental Social Psychology, Volume 46, Issue 5, pp. 701-708, September, 2010). It was reported that this synchronization of body movements relates to an increase in a positive relationship between people (Miles et al. “Too Late to Coordinate: Contextual Influences on Behavioral Synchrony”. European Journal of Social Psychology, Issue 40, pp. 52-60, September 2009).
As mentioned above, synchronization of unconscious behaviors causes not only synchronization of bodies but also synchronization of biological reactions and a positive effect. However, a sympathetic reaction is very important in interactions between people, and may differently appear according to with whom a person maintains a social relationship and communicates. This social relationship is socially strong or weak. However, current studies into social relationships are not considered in synchronization. Accordingly, it is expected that there is a difference in the degree of synchronization between physiological reactions according to social relationships. This is because physiological reactions generated according to social relationships are unconscious. It has been recently reported that synchronization of physiological reactions effectively affects maintenance and increase of a social relationship.